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Universal Electron Injection Dynamics at Nanointerfaces in Dye‐Sensitized Solar Cells
Author(s) -
Wang Lei,
Wang HaiYu,
Fang HongHua,
Wang Hai,
Yang ZhiYong,
Gao BingRong,
Chen QiDai,
Han Wei,
Sun HongBo
Publication year - 2012
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201102550
Subject(s) - materials science , dye sensitized solar cell , electron transfer , nanocrystalline material , electron , quantum dot , coupling (piping) , semiconductor , chemical physics , photovoltaic system , nanotechnology , optoelectronics , physics , photochemistry , quantum mechanics , chemistry , ecology , electrode , biology , electrolyte , metallurgy
Initial nanointerfacial electron transfer dynamics are studied in dye‐sensitized solar cells (DSSCs) in which the free energy and kinetics vary over a broad range. Surprisingly, it is found that the decay profiles, reflecting the electron transfer behavior, show a universal shape despite the different kinds of dye and semiconductor nanocrystalline films, even across different device types. This renews intuitive knowledge about the electron injection process in DSSCs. In order to quantitatively comprehend the universal behavior, a static inhomogeneous electronic coupling model with a Gaussian distribution of local injection energetics is proposed in which only the electron injection rate is a variant. It is confirmed that this model can be extended to CdSe quantum dot‐sensitized films. These unambiguous results indicate exactly the same physical distribution in electron injection process of different sensitization films, providing limited simple and important parameters describing the electron injection process including electronic coupling constant and reorganization energy. The results provide insight into photoconversion physics and the design of optimal metal‐free organic dye‐sensitized photovoltaic devices by molecular engineering.